Everyone agrees that both folate and its synthetic form, folic acid, are good for your brain.
There is concern, however, that ingesting folate/folic acid could hide a lack of vitamin B-12, which could lead to mental deterioration and other nervous system problems.
Many studies have found that high levels of folate intake, up to 800 micrograms a day, may help ward off the decline in information processing, lower the risk of Alzheimer's disease and even improve mental sharpness.
Folate/folic acid is also vital for the health of a developing fetus, which is why the Food and Drug Administration in 1998 mandated folic acid supplementation for grain products sold in the United States.
Vitamin B-12 plays an essential role in red blood cell formation, cell metabolism and nerve function. B-12 deficiency can cause persistent tingling in the hands and feet, confusion and forgetfulness.
According to the July 2007 Mayo Clinic Health Letter, an estimated 15 percent of older adults have too little vitamin B-12. This can be caused by age-related changes in the digestive tract, which inhibit the body's ability to absorb the vitamin from food. Vegetarians who avoid all animal products and people who have digestive diseases such as celiac or Crohn's disease are also at increased risk of vitamin B-12 deficiency.
While folate/folic acid is equally important for our health, there are concerns about how it reacts with vitamin B-12 inside the body. Scientists suspect that high folate/folic acid intake can correct anemia — the most obvious symptom of vitamin B-12 deficiency. When this occurs, however, vitamin B-12 deficiency may go undetected and the nervous system deterioration it causes may continue.
More research is needed to fully explore the relationship between folate/folic acid and vitamin B-12 and how it affects brain health. Until then, the safest bet is to ensure intake of adequate amounts of both. Most older adults can do this by eating a healthy diet that includes daily servings of fortified breads, grains or cereals and a wide variety of fresh and natural foods such as fruits, vegetables, beans and nuts — or by taking a multivitamin supplement that contains 100 percent of the recommended daily allowance of both folate/folic acid and vitamin B-12. For folic acid, that's 400 mcg a day and for vitamin B-12, it's 2.4 mcg a day.